Year: 2026
Type: article
Abstract: We present a solvable same-sector effective theory for anomaly-inspired axion inflation, in which a heavy trace-anomaly mode dynamically backreacts on the axion potential. The tree-level elimination of the radial field resums the backreaction into a closed-form Lambert- W potential, naturally flattening the hilltop potential without external plateau operators. By deriving the exact trough metric, we evaluate all the observables on the fully reduced one-field action, bypassing uncontrolled kinetic approximations. Calibrated at N ★ = 56, reheating-compatible branches yield r ≃ 0.033–0.036 and α s ≃ -(4.6–4.7) × 10 -4 , comfortably satisfying the current ACT/SPT/BICEP constraints. The evolution remains strictly adiabatic ( m ⊥ 2 / H 2 ≳ 6.1, Ω/ H ≲ 7.6 × 10 -4 ) with negligible sound-speed and metric corrections. We provide analytic control over the constant- w eff reheating map, the N re = 0 boundary, and robustness against vacuum-offset deformations. This Lambert- W backbone establishes a precise, deformable benchmark for confining axion inflation, with microscopic matching and reheating microphysics accessible as systematic EFT refinements.
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7154742645